Transfer ownership of PyPI packages
Update: PEP 541 has been approved on 2018-03-23. There is additional work to be done before you could request an ownership transfer, however.
My original answer follows.
The PEP is in draft stage. As such it is not official policy and requests are not likely to be honoured.
If the PEP ever moves to the accepted stage, the terms of service would need to be updated to reflect the new policy. And it may well be that packages that were uploaded before this point in time to be grandfathered in; they were uploaded under the old terms after all. All in all, it'll be some time before packages that are abandoned today can be claimed.
What is in place today is an ad-hoc process, executed without any real mandate or support in the terms of service, based more on common sense than on actual legal standing. There is no telling how long a request will take or what your chances are.
For some background, you can read this thread from 2014 that appears to be the first serious call for a formal process; it was kicked off after a request for control of the django-registration package back-fired with the original maintainer removing a newly-added maintainer. The whole issue came back up again in January 2017, which led to the first draft of PEP 541 (Donald is Donald Stufft, the current maintainer of PyPI).